SIDISTAR® T 120U an undensified amorphous, spherical silicon dioxide compatible with all thermoplastic systems. It acts as a flame retardancy synergist for thermoplastics and as a nucleating agent for PVC foam.


SIDISTAR® T120U is a specially designed light-coloured process modifier consisting of spherical, submicron particles of amorphous silicon dioxide. The nature of the product allows excellent dispersion of these particles in the polymer matrix. This leads to improved dispersion of all compound ingredients and a better flow, allowing higher extrusion speeds and smoother surface of the end product.. The product is supplied in an undensified form. 


SIDISTAR® T120U  has been designed for usage in thermoplastics. Areas of use include flame retardant cable compounds; Foamed PVC etc.

This undensified version is specifically designed for improved dispersion in low melt-viscosity systems.

Storage conditions

The product is recommended to be stored in a covered dry place, protected from direct UV light. Recommended storage temperature between +5 ºC and +40 ºC (+45ºF and +104ºF) . It’s important that the minimum temperature is > 5ºC (9ºF) above the dew point. Recommended relative humidity < 85%. 

Shelf life

We recommend that the product should be used within 2 years from production date.

Physical data and chemical properties

PropertiesTest methodUnitLimits
SiO2 (Silicon dioxide, amorphous) ESM-LAB-18 % 96.0 - 99.0
C (Carbon) ESM-LAB-05 % ≤ 0.20
Fe2O3 (Iron oxide) ESM-LAB-17 % ≤ 0.25
H2O (Moisture, when packed) ESM-LAB-02 % ≤ 0.8
Loss on Ignition (L.O.I.) @ 950o C ESM-LAB-03 % ≤ 0.60
Coarse particles >45µ (325 mesh) ESM-LAB-09 % ≤ 0.10
pH-value (fresh) ESM-LAB-10   7 - 9
Bulk Density (when packed) ESM-LAB-08 kg/m3 150 - 350


Other properties (Measured on undensified material)UnitTypical values*
Specific surface area (BET) m2/g 18 - 25
Median particle size μm 0.15
L-value % ≥ 90.0
Specific Gravity   2.2

*Typical values are for indicational use only, values are not part of Elkem Silicon Materials standard analysis.

Test methods

Material data given in this product specification refer to analysis according to Elkem internal standard test methods, which are available upon request.


DescriptionBig bagsSmall bags
Bag on pallet 1 big bag 40 small bags
Net weight 1 bag 400 kg 15 kg
Net weight on pallet 400 kg (881 lb) 600 (1323 lb)
Gross weight

400 + 20 = 420 kg
(881 + 44 = 925 lb)

600 + 20 = 620 kg
(1323 + 44 = 1367 lb)

Bag dimension (L x W x H)

106 x 106 x 142 cm
(41.7 x 41.7 x 55.9 in) 

73 x 46 x 20 cm
(28.7 x 18.1 x 7.9 in)

Discharge spout

42 cm (16.5 in)
70 cm (27.6 in)


Bag material 

Coated woven polypropylene fabric 

Multilayer paper bag
with PE liner

Cover / protection 

LDPE shrink hood 

LDPE shrink hood 


Fumigated wood 

Fumigated wood

Pallet dimensions incl bags
(L x W x H)

105 x 105 x 147 cm
(41.3 x 41.3 x 57.9 in) 

120 x 100 x 180 cm
(47.2 x 39.4 x 70.9 in)